1. Field of the Invention
The present invention relates to a key for opening a lock or latch.
2. Description of the Related Art
Keys are a common everyday tool used by nearly all of the population. Keys are used to restrict access to residential and commercial structures, automobiles, bicycles, post office boxes, toolboxes, moneyboxes, cash resisters, etc. The basic structure of a key has remained essential unchanged since its initial inception. Basically, a key includes a grip, which is held between the thumb and fingers of the user. A lock or latch engaging portion, such as a shaft is rigidly fixed to the grip, and coding is provided on the shaft. Typically the coding includes notches along one or two edges of the shaft and one or more grooves extending along the shaft.
Common keys suffer a major drawback. Often a lock will become difficult to operate with a key. The difficulty is usually due to the coding on the key's shaft becoming worn, or slight corrosion or contamination building up inside the lock's mechanism. Cutting a new key, or applying a cleaner/lubricate to the lock mechanism, can easily rectify these conditions. However, instead of fixing the problem, it is common that the person possessing the key will simply exert additional torque to the key in order to force the lock or latch to open.
Forcing the key to turn the lock may work for some period of time, however the additional applied torque causes the connection between the grip and shaft of the key to fatigue, and can also damage the lock's internal mechanism. Eventually, the connection between the grip and shaft will fail, and the key's shaft will be broken off inside the lock. When such an event occurs, it is very time consuming to remove the key's shaft from the lock. Usually, the lock must be removed and disassembled to remove the key's shaft, then reassembled and reinstalled. Often, it is more cost effective to throw away the lock and replace it with a new lock.
Therefore, there exists a need in the art for a key, which will not permit the key's operator to apply excessive torque when attempting to open the lock. Such a key would remind the key's operator to take the proper corrective action to fix the problem, e.g. clean/lubricate the lock or replace the worn key, instead of continuing to apply more and more torque to the key to open the lock. Further, such a key would reduce the labor associated with repairing a lock's mechanism to remove a broken key shaft, and the wasteful replacement of locks which are in good operating order except for the presence of the key's broken shaft lodged inside.